Apparatus for the control of highway crossing signals



June 21, 1932. L 1,864,179

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Filed Oct. 22, 1950 Interlocking Relay InterLocking Relay INVENTOR H92, f a. w. B2,

aim-W /w ATTORNEY" Patented June 21, 1932 UNITED STATES CHARLES BELL, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOB, TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION .OF

PENNSYLVANIA APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Application filed October 22, 1930. Serial No. 490,456.

My invention relates to apparatus for the control of highway crossing signals, that is,

si nals located at intersections of railways a diagrammatic view illustrating one form of apparatus embodying my invention. Fig. 2 is a similar view showing a modified form of the apparatus illustrated in Fig. 1,- and also embodying my invention; v

Similar reference characters refer to similar parts inboth views. I

Referring first to Fig; 1, the reference characters 1 and 1 designate the track rails of a stretch of railway track which is intersected by a highway H,and over which traffic normally moves in both directions. Located on opposite sides of the railwayadja cent the intersection of the railway and the highway are two highway crossing signals S and S the function of which is to give a warning indication when a train is approaching the highway from either direction. These signals may be of any suitable type, but as here shown, they are similar to those commonly employed at street intersections, and each comprises a proceed lamp G, a preliminary warning lamp Y, and a stop lamp R.

The track railsof the railway are divided, by means of insulated joints 2, to form a plurality of track sections D-E, EF, FJ and JK, the junction of the sections E F and FJ preferably being located at or near the highway crossing H.- Connected across the rails of each section at the end farthest away from the highway is a suitable source of track circuit current, here shown as a track battery 3, and connected across the rails ofsections 13-15 and J K at the end nearest the highway are two track relays T PATENT OFFICE I T and T respectively. One magnet 4 of an i if interlocking relay L is connected with the rails of section E-F adjacent the highway H, and the other magnet 4 is similarly connected with the rails of section 'F- e The interlocking relay'L maybe of any of the well known types, such for example, as the relay illustrated in United States Letters Patent No. 799,452, granted to Coleman on September 12, 1905,: and as here shown, is provided with two front contacts 6 and Wand a back contact 8 which are controlledby the magnet 4 and with two front contacts 6 and 7 and a back contact 8 which are controlled by the magnet 4 If magnet 4* becomes deenergized before magnet 4 becomes deenergized, frontconf tacts G 'and 7 will become opened, and back contact 8 will become closed. If magnet-4s becomes deenergized subsequent to magnet 4 however, front contacts 6 and 7* will become opened, but back contact 8 will remain open. Similarly, if magnet 4 becomes deenergized before the magnet 4*, front contacts 6 and 7 will become opened and back contact 8 will become closed, but if magnet 4 becomes deenergized subsequent to zmagnet l front contacts'fi and 7? will become opened and contact 8 will remain open. f

The interlocking relay L and the track relays T and T control a second. interlocking relay L which is similar to the interlocking relay L except that magnet 4* of relay L controls a fiagman ;contact 9 'and a back contact 10 whilemagnet 4 controls "a flagman contact 9 anc1'a back contact 10*. The back contacts 10 and 10 of the relay L operate in the same manner-as the back contacts 8 and 8 of the relay L The fiagman contacts 9,;however, are so 'arranged that these contacts will be closed either when the associated magnet is energized or has become deenergized subsequent to the deenergization of the other'magnet but not when the associatedmagnet becomes deenergized while the other magnet is energized. r Magnet 4 ofinterlo'cking relay L is pr0- 'vided with a circuitwhich passes from ter minal'B of a suitable source of current not 11 of track relay T front contact 6 of interlocking relay L and magnet 4 of interlocking relay L to the other terminal C of the source. Similarly, magnet i of interlocking relay L is provided with a circuit which passes from terminal B, through front contact 12 of track relay T front contact 6 of interlocking relay L and magnet 4 to terminal C The interlocking relays L and L jointly control the signals S and S Considering signal S for example, the lamp G of this signal is provided with a circuit which passes from terminal B, through fiagman contacts 9 and 9 of interlocking relay L and the filament of lamp G to terminal G. Then this circuit is closed, lamp G is lighted and signal Stdisplays a proceed indication. The lamp Y of signal S is provided with a circuit which passes from terminal B, through back contact 10 of interlocking relay L front contact 7 of interlocking relay L and the filament of lamp Y to terminal'G. Lamp Y of signal S is alsosprovided with another circuit which passes from terminal B, through back contact 10 of interlocking relay L front contact 7 a of interlocking relay L and the filament oflamp Y to terminal C. When either of the circuits just traced-is closed, lamp Y is lighted, and signal S displays a preliminary warning indication. The lamp R of signal S is also provided with two circuits, one of which passes from terminal B, throughback contact 8 of interlocking: relayL and the filament of lamp R to terminal C, and the other of which passes from terminal B, through back contact .8 ofinterlocking relay L and the filament of lamp R to terminal C. When either of these circuits is closed, lamp R is lighted, and signal S displays a stop indication. Each of the. lamps of signal S is connected in multiple. with the corresponding lamp of signal S and it will be apparent therefore that when a lamp of one signal becomes lighted, the corresponding lamp of the other signal will also become lighted.

As shown in the drawing, sections D-E, EF, F-J and J.--K are all unoccupied, so that track relays T and T and bothmagnets 4* and at of interlocking relay L are all energized. The circuits previously traced for the magnets P-and 4c of interlocking relay L2 are therefore closed, and both of these magnets are therefore energized. The circuits'for the proceedlamps G of both signals S and S are therefore closed at flagman contacts 9 and 9? of interlocking relay L? and. both of. these lamps are'lighted to indicate that traffic on the highway may proceed across the railway:

- I will now assume that'a train moving'from left to right'enters section D -E. This will cause track relay T. to become deenergized and. open its front contact; 11, which will interrupt the circuit for magnet 4: of interlocking relay L and so deenergize this magnet. Flagman contact 9 of relay L. will therefore become opened, and back contact 10 will become closed. The opening of flagman contact 9* will interrupt the circuit for the proceed lamps G of the signals S and S and the closing of back contact 10 will complete one of the circuits for the preliminary warning lamps Y of these signals. The proceed lamps G will therefore become extinguished, and the preliminary warning lamps Y will become lighted. The preliminary warning lamps will now remain lighted until the train enters section EF and deenergizes magnet 43 of interlocking relay Lt. When this happens, front contacts 6 and 7 of interlocking relay L will become opened, and back contact 8 will become closed. The open ing of frontcontact 6 will interrupt the circuit formagnet 4 of interlocking relay L at this contact and, hence, will prevent this magnet from becoming energized when front contact 11 of track relay T subsequently becomes energized due to therear end of the train having passed completely out of section 13 E. The opening of front contact 7 of interlocking relay L will interrupt the circuit which was previously closed for the preliminary warning lamps Y at this contact, 0

and the closing of back contact 8 will complete one of the circuits for the stop lamps R. The preliminary warning lamps Y will therefore become extinguished, and the stop lamps R will become lighted. When the train enters section :F-J, magnet 4 of relay L will become deenergized, so that relay L will now open its front contacts 6 and 7 The openingof front contact 6* of interlocking relay L will interrupt the circuit for magnet 49 ofinterlocking relay L and this magnet will also become deenergized. Flagman contact 9 of this relay will remain closed, however, and back contact 1O will remain open under these conditions due to the operation of the relay pointed out hereinbefore. When the train has passed completely out of section E-F, magnet 4 of interlocking relay L will again become energized so that front contacts 6 and 7 will again become closed, and back contact 8 willbecome opened. When back contact 8 becomes opened, the circuit which was previously closed for the stop lamps R at this contact will be opened, and these lamps will become extinguished. Since front contact 11 of track relay T is now closed, the closing of front contact 6 will complete the circuit for magnet 4: of interlocking relay L andmagnet 4- will therefore become energized. Flagman contact 9 will therefore become closed and back contact 10 will become opened. The closing-of flagman contact 9* will complete the circuit for the proceed lampsG of signals S and S and these lamps will therefore become lighted. When the train enters section J.K, track relay T will become deenergized, and will open its front contact 12, but since the circuit for magnet 4 of interlocking relay L is already open at front contact 6 of interlocking relay L this will have no efiect on the remainder of the apparatus. When the train passes out of section FJ, magnet 4 will again become energized. This will cause front contacts 6 and 7 to become closed but will otherwise have no effect on the apparatus. When the train has passed completely out of section J-K, track relay T willagain become energized and will close its front contact 12. This will cause magnet 4 of interlocking relay L to become energized, thereby restoring the parts to their normal positions in which they are illustrated in the drawing.

lVhen a train moving from right to left traverses the stretch of track illustrated in the drawing, the operation of the apparatus will be exactlythe reverse of that just described, and will be readily understood from an inspection of the drawing without tracing the sequence of operation in detail.

Referring now to Fig. 2, the apparatus here shown is similar to that shown in Fig. 1 with the exception that, as here shown, relay L is provided. in addition to the contacts shown 7 in Fig. l, with two flagman contacts 13 and.

13 which operate-in the same manner as the flagman contacts 9 and 9 of relay L shown in Fig. 1, and which are utilized to control the proceed lamps G of the signals S and S in place of the flagman contacts 9 and 9 shown in Fig. 1. The circuits for these lamps will be obvious from an inspection of the drawing.

With the apparatus constructed as shown in Fig. 2, when a train moving toward the right enters section DE' and deenergizes track relay T magnet 4 of interlocking relay L will become deenergized as before, and will close its back contact 10 This will close one of the circuits for the preliminary warning lamps Y, and these lamps will become lighted. Since the proceed lamps G are now controlled by the flagman contacts 13* and 13", these lamps will remain lighted, and, as a result, the signals S and S instead of having only the preliminary warning lamps lighted under these conditions, as was the case with the apparatus illustrated in Fig. 1 will have both the proceed and preliminary warninglamps lighted. When the train enters section EF, magnet l? of relay L will become deenergized, which will cause'front'contacts 6 and 7 and flagman contact 13 of this relay to become opened and back contact 8 to become closed. The opening of flagman contact 13* will open the circuit for the proceed lamps G, and the open ing of front contact 7 will open the circuit for the preliminary warning lamps Y, while the closing of contact 8 will complete one of the circuits for the stop lamps R. Theproceed lamps G and preliminary warning lamps Y will therefore become extinguished, and the stop lamps R will become lighted. When the train enters section FJ, magnet 4 of interlocking relay L will become deenergized, and front contacts 6 and 7 b of this relay will therefore open, but back contact 8 will remain open and'fiagmancontact 13 will remain closed. The opening of front contact 6 will deener gize magnet P'of interlocking relay L but this relay will not close its back contact 10. WVhen the train has passed completely out of section E-F, magnet 4 of interlocking relay L will'again become energized, and this will cause front contacts 6 and 7 and flagman" contact 13 to again become closed, and back contact 8 to become open. Since contact 11 of track relay T is then closed, the closing of front contact 6 will complete the circuit for mag net 4 of interlocking relay L and this re lay will open its back contact 10 The opening of back contact 8 of interlocking relay L will interrupt the circuit for the stop lamps R, and since fiagman contact 13 remained closed when magnet 4t of interlocking relay L becamedeenergized, the closing of flagman contact 13 will complete a circuit for the proceed lamps G. The stop lamps R will therefore become extinguished and the proceed lamps will become lighted. When the train enters section JK, track relay T will become deenergized, but this will not afiect the remainder of the apparatus. When the train has passed completely out .of section F J magnet l of interlocking relay L will become energized, so that front contacts 6 and 7 will again become closed.

This

also will have no'effect on the remainder of the apparatus. When the train has passed out of section JK, track relay T will pick up,and since front contact-6 of relay L is then closed, this will complete the circuit for magnet 4 of interlocking relay L This magnet will then become energized, and the apparatus will be restored to its normal con-, dition in which it is illustrated in the drawst i If a train moving toward the left traverses the stretch oftrackshown in Fig. 2, the operation of the apparatus will be substantially the reverse of that just described, and will be readily understood from an inspection of the drawing,

One advantage of apparatus embodying my invention is that it provides means whereby the indications commonly accepted and usually displayed at intersections of highways or streets can be applied at the point of intersection of highways with railways. I

Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modificatlons may be made therein within the scope of the appended claims without departingfrom the spirit and scope ofrny invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track divided into first, second, third and fourth successive sections; a highway intersecting said stretchat substantially the junction of said second and third sections, a first interlocking relay having one magnet connectedwith therailsof said secondsection and having the other magnetconnected with the rails of said third section, a first track relay connected with the rails of said first section and a second track. relay connected with the rails of said fourth section, four sources of track circuit current one connected with the rails of each section, a second interlocking relay having its one magnet controlled by said first track relay and said one magnet of said first interlocking relay and having its other magnet controlled by said second track rela and said other magnet of said first interlocking relay, and a highway crossing signal located at the intersection of said railway track and said highway and controlled by said two interlocking relays. I v

2. In combination, a stretch of railway trackdivided into. first, second, bird, and fourth successive sections; a highway intersecting said stretch at substantially the junction of said second and third sections, a first interlocking relay having one magnet connectcd with the rails of said second section and having the other magnet connected with the rails of said third section, a first track relay connected with the rails of said first section and a second track relay connected with i the rails of said fourth section, four sources 1 first interlocking relay and having its other magnet controlled by said second track relay and said other magnet ofsaidfirst interlocking relay, a highway crossing signal located at the intersection of said railway track and said highway and comprising a proceed lamp, a preliminary warning lamp, and a stop lamp; means controlled by both magnets of said second interlocking relay for controlling said proceed lamp, means controlled by said one magnet of said first interlocking relay and said one magnet of said second interlocking relay for at times controlling said preliminary warning lamp .and by said other magnet of said first interlocking relay and said other magnet of said second interlocking relay for at other times controlling said preliminary warning lamp, and means controlled at times by said one magnet of said first interlocking relay andat-other times by said other magnetofsaid first interlocking relay forcontrolling said stop lamp.

3. In combination, a stretch of railway track divided into first, second, third, and fourth successive sections; a highway intersecting said stretch at substantially the junction of said second and third sections, a first interlocking relay having one magnet connected with the. railsof said second section and having the other magnetconnected with the rails of said third section, a first track relay connected with the rails of said first section and a, second. track relay connected with the rails of said fourth section, four sources of track circuit current one connected with the rails of each section, a second interlocking relay having its one magnet controlled by said first track relay and said one magnet of said first interlocking relay and having its other magnet controlled by said second track relay and said other magnet of said first interlocking relay, a highway crossing signal capable ofdisplaying three indications located at the intersection of said railway track. and said highway, means controlled by both magnets of said second interlocking relay for causing said signal to display a first one of 'said' indications, means controlled by said one magnet of said first interlocking relay and said one magnet of'said second interlocking relay for at times causing said signal to display a second one ofsaidindications andby said other magnet of said first interlocking relay and said other'magnet'of said second interlocking relay for at other times causing said signal to display said second indication. and means controlled by said one magnet of said first interlocking relay for at times causing said signal to display a third one of said indications and by said other magnet of said first interlocking relay for at other times causing said signal to display said third indication.

a. In combination; a stretch of railway track divided into first, second, third, and fourth successive sections; a highway intersecting said stretch at substantially the junction of said second and third sections, a track circuit for said first section including a track relay, a track circuit for said fourth section including a second track relay, a first interlocking relay comprising two magnets and front and back contacts controlled by each of said magnets, a second interlocking relay comprising two magnets and back and flagman contacts controlled by each of said magnets; a track circuit for said second section including one magnet of said first interlocking relay, a track circuit for said third section including the other winding of said first interlocking relay, a circuit for one magnet of said second interlocking relay including a front contact of said first track relay and a front contact controlledby-said one magnet of said first interlocking relay, a circuit for the other magnet of'said second interlocking relay including a front contact of said second track relay and a front contact controlled'by said other magnet of said first interlocking relay, a highway crossing signal-located adjacent the intersection of said stretch and said highway and provided with a proceed lamp, a preliminary warning lamp, and a stop lamp; a circuit for said proceed lamp including a fiagman contact controlled by said one magnet of said second interlocking relay and a flagm-an contact controlled by said other winding ofsaid second interlocking relay, a circuit for saidpreliminary warning lamp including afront contact controlled by said one winding'of said first interlocking relay and a back contact controlled by said one winding of said second interlocking relay, and acircuit for said-stop lamp including a back contact controlled by said one winding of said first interlocking relay connected in multiple with a back contact controlled by said other winding of said first interlocking relay. I r

' 5. In combination; a stretch of railway track divided into first, second, third and fourth successive sections; a highway intersecting said stretchat substantiallythe junction of said second and third sections, a track circuit for said'first section including a first track relay, a track circuit for said fourth section including a second track relay, a first interlocking relay comprising two magnets and front and back contacts controlled by each of said magnets, a second interlocking relay comprising two magnets and back and fiagman contacts controlled by each of said magnets; a track circuit for said second section including one magnet of saidfirst interlocking relay, a track circuit for said third section including the other winding of said first interlocking relay, a circuit for one magnet of said second interlocking relay including a front contact of said first track relay and a front contact controlled by said one magnet of said first interlocking relay, a circuit for the other magnet of said second interlocking relay including a front contact of said second track relay and a front'contact controlled by said other magnet of said first interlocking relay, a highway crossing signal located adjacent the intersection of.

said railway track and said highway and provided with a proceed lamp, a preliminary warning lamp, and a stop lamp; a circuit for said proceed lamp including a flagman contact controlled by said one magnet'ofsaid second interlocking relay and a flagman contact controlled by said other winding of said second interlocking relay, a first circuit for said preliminary warning lamp including a front contact controlled by said one winding ofsaid first interlocking relay and a back contact controlled by said one winding of said second interlocking relay, a second circuit for said preliminary warning lamp including a front contact controlled by said other winding of said first interlocking relay and a back contact controlled by said other winding of said second interlocking relay, and a circuit for said stop lamp including a back contact controlled by said one winding of said first interlocking relay connected in multiple with a back contact controlled by said other winding of said first interlocking relay.

6. In combination, a stretch of railway track divided'into first, second, third and fourth successive sections, a highway intersecting said stretch at substantially the junction of said second and third sections, a first interlocking relay having one magnet connected with the rails of said second section and having the other magnet connected with the rails of said third section, a first track relay connected with the rails of said first section and a second track relay connected with the rails of saidtfourth section, four sources of track circuit current one connected with the rails of each section, a second interlocking relay provided withtwomagnets, means for energizing one magnet ofsaid second inter lockingrelay when andonly when saidfirst trackrelay and said one magnet of said first interlocking relay are both energized, means for energizing the other magnet of said second interlocking relay when and only when said second track relay and. said other mag-v net of said first interlocking relay are both energized; a highway crossing signal located at the intersection of said railway track and i said highway and comprising a proceed lamp, a preliminary warning lamp, and a stop lamp; means effective when both magnets of said second interlocking relay are energized for energizing said proceed lamp, means effec-V tive when said one magnetof said firstinter locking relay is energized and said one magnet of said second interlocking relay is deen: ergized'for at times energizing said prelimi-. nary warning lamp, means efiective when said other magnet of said first interlocking relay is energized and said other magnet of said second interlocking relay is deenergized for at other times energizing said preliminary Warning lamp, and means effective when either of said first interlocking relay becomes deenergized previous to the deenergization of the other magnet of this relay for energizing said stop lamp. i a

7 In combination, a stretch of railway track divided into first, second, third and fourthsuccessive sections, a highway intersecting said stretch at substantially the junction of said second and third sections, a first interlocking relay having one magnet connected with the rails of said second section and having the other magnet connected with the rails of said third section, a first track relay connected with the rails ofsaid first section and a second track relay connected with the rails of said fourth section, four sources of track circuit current one connected with the rails of each section, a second interlocking relay provided with two magnets, means for energizing one magnet of said second interlocking relay when and only when said first track relay and said one magnet of said first interlocking relay are both energized, means for energizing the other magnet of said second interlocking relay when and only when said second track relay and said other magnet of said first interlocking relay are both energized, a highway crossing signal locatedat the intersection of said railway track and said highway and comprising a proceed lamp, a preliminary warning lamp, and a stop lamp; means efi'ective when both magnets of said first interlocking relay are energized for energizing said proceed lamp, means effective when said one magnet of said first interlocking relay is energized and said one magnet of said second interlocking relay is deenergized for at times energizing said preliminary warning lamp, means effective when said other magnet of said first interlocking relay is energized and said other magnet of said second interlocking relay is deenergiz'ed for at other times energizing said preliminary warning lamp, and means effective when either magnet of said first interlocking relay becomes deenergized previous to the deenergization of the other magnet of this relay for energizing said stop lamp.

8. In combination, a stretch of railway track divided into first, second, third and fourth successive sections, a highway intersecting said stretch at substantially the junction of said second and third sections, a first interlocking relay having one magnet connected with the rails of said second section and having the other magnet connected with the rails of said third section, a first track relay connected with the rails of said first section anda second track relay connected with the rails of said fourth section, four sources of track circuit current one connected with the'rails of each section, a second interlocking relay provided with two magnets, means for energizing one magnet of said second interlocking relay when and only when said first track relay and said one magnet of said first interlocking relay are both energized mea-ns for energizingthe other magnet of said second interlocking relay when and only when said second track relay and said other magnet of said first inter-loci;-

.ing relay are both energized; a highway crossing signal located at the intersection of said stretch and said highway and compris inga proceed lamp, a preliminary warning lamp, and'a' stop lamp; means effective when both magnets of said first interlocking relay are energized or when one magnet of said first interlockingrelay-has again-become energized subsequent to the previous deenergization of both magnets forenergizing'said proceed lamp, means eiiective when said one magnet of said first interlocking relay is energized and said one magnet ofsaid second interlocking relay is deenergized for at times engaging said preliminary warning lamp,means eiiec-tive when said other magnet of said first interlocking relay is energized and said other mag-net of said second interlocking relay isdeenergized for at other times energizing said preliminary warning lamp, and means effective when either magnet of said first interlockingrelay becomes deenerg-ized previous to the' deenergization of the'other magnet of the relay for energizingsaid stop :lamp. a

9. In combinatioma stretch of railway track divided into g'first, second, third and fourth successive sections, a highway intersecting said stretch at substantially the junction ofsaid second and third sections, a first interlocking relay having one magnet connected with the rails of said second section and having the other magnet connected with the rails of saidthirdsection, a first track relay connected with the rails of said first section and a second track relay connected with the rails of said fourth section, four sources of track circuit cur-rent one connected with the rails 'ofeach section, a second interlocking relay provided with two magnets, means tor energizing one magnet of saidse- 0nd interlocking relay-when and only when s'aidfirst track relay and said One magnet of said first interlocking relay are both energized, means for energizing the other magnet of said second interlocking relay when and only when said second track relay and said other magnet of said first interlocking relay are both energized; a highway crossing signal located adjacent the intersection of said stretch and said highway and comprising a proceed lam a preliminarywarning lamp, and astop lamp; means efiective when 'both magnets of said second interlocking relay are energized or when one magnet of said second interlocking relay has again become energized subsequent to the previous d'eenergization of both magnets for energizing said proceed lamp, imeanseflfective when said one magnet of said first interlocking relay is energized and said one magnet of said second interlocking relay is deenergized for at times energizing said preliminary warning lamp, means effective when said other mag net of said "first interlockingrelay is energized andsaid other magnetof said'second interlo'oking relay is deenergized for at other times energizing said preliminary warning lamp, and means efi e'c-ti've when either magnet ofsaid first interlocking relay becomes deenergized previous to the deenergizationoi the other magnet of this relay for energizing said stop lamp.

10. In combination; a stretch of railway track divided into first, second, third and fourth successive sections; a highway inter-V secting said stretch at substantially the junction of said second and third sections, a track circuit for said first section including a first track relay, a track circuit for said fourth section inluding a second track relay; a first interlocking relay comprising a first and second magnet, a first and second contact controlled by said first magnet in such man ner that said first and second contacts are closed when and only when said first magnet is energized, a third contact controlled by said first magnet in such manner that said third contact is closed when and only when said first magnet has become deenergized previous to the deenergization of said second magnet, a fourth and fifth contact controlled by said second magnet in such manner that said fourth and fifth contacts are closed when and only when said second magnet is energized, and a sixth contact controlled by said second magnet in such manner that said sixth contact is closed when and only when said second magnet has become deenergized previous to the deenergization of said first magnet; a track circuit for said second section including said first magnet, a track circuit for said third section including said second magnet; a second interlocking relay comprising a third and fourth magnet, a seventh contact controlled by said third magnet in such manner that said seventh contact is closed when and only when said third mag: net has become deenergized previous to the deenergization of said fourth magnet, an eighth contact controlled by said third magnet in such manner that said eighth contact is closed at all times except when said third magnet becomes deenergized previous to the deenergization of said fourth magnet, a ninth contact controlled by said fourth magnet in such manner that said ninth contact is closed when and only when said fourth magnet has become deenergized previous to the deenergization of said third magnet, a tenth contact controlled by said fourth magnet in such manner that said tenth contact is closed at all times except when said fourth magnet has become deenergized previous'to the'deenergization of said third magnet, a circuit for said third magnet including a front contact of said first track relay and said first contact, a circuit for said fourth magnet including a front contact of said second track relay and said fourth contact; a highway crossing signal located adjacent the intersection of said railway'track and said highway and provided with a proceed lamp, a. preliminary warning lamp, and a stop lamp a circuit for said proceed lamp including said eighth and tenth contacts, a

first circuit for said preliminary warning lamp including said second contact and said seventh contact, a second circuit for said pre liminary warning lamp inlud-ing said fifth and said ninth contacts, a first circuit for said stop lampincluding said third contact, and a second circuit for said stop lamp including said sixth contact. I v

11. In combination; a stretch of railway track divided into first, second, third, and fourth successive sections; a highway intersecting said stretch at substantially the junction of said second and third sections, a'track circuit for said first section including a first track relay, a track circuit for said fourth section including a second track relay, a first interlocking relay comprising a first and second magnet, a first and second contact controlled by said first magnet in such manner that said first and second contacts are closed when and only when said first magnet is energized, a third Contact controlled by said first magnet in such mannerthat said third con tact is closed when and only when said first magnet has become deenergized previous to the deenergization of said secondmagnet, a fourth contact controlled by said first magnet in such manner that said fourth contact isclosed at all times except when said first magnet becomes deenergized previous to the deenergization of said second-magnet, a fifth and sixth contact controlled by said second magnet in such manner that said fifth and sixth contacts are closed when and only when said second magnet is energized, a seventh contact controlled by said second magnet in such manner that said seventh contact is closed when and only when said second maglist has become deenergized previous to the deenergization of said first magnet, and an eighth contact controlled by said second magnet in such manner that said eighth contact is closed at all times except when said second magnet becomes deenergized previous to the deenergization of said first magnet, a track circuit for said second section including said first magnet, a track circuit for said third section including said second magnet; a second interlocking relay comprising a third and fourth magnet, a ninth contact controlled by said third magnet in such manner that said ninth contact is closed when and only when said third magnet has become deenergized previous to the deenergization of said fourth magnet, and a tenth contact controlled by said fourth magnet in such manner that said tenth contact is closedwhen and only when said fourth magnet has become deenergized previous to the deenergization of said third magnet; a circuit for said third magnet including a front contact ofsaid first track relay and said first contact, a circuit for said fourth magnet including a front contact of said second track relay and said fifth contact;

a highway crossing signal located adjacent the intersection of saidrailway track and said highway and provided with a proceed lamp, a preliminary warning lamp, and a stop lamp; a circuit for said proceed lamp including said fourth and eighth contacts, a first circuit forsaid preliminary warning lamp including said second contact and said ninth contact, a second circuit forsaid preliminary warning lamp including said sixth and said tenth contacts, a first circuit for said 1 on said stretch for causing said signal to display a first one of said indications, means effective when a train enters said stretch and until the train has passed a first point located a predetermined distance in rear of said highway for causing said signal to display a second one of said indications, and means efi'ectiveafter said train has passed said first point and until the train has passed the highway for causing said signal to display the third one of said indications.

13. In combination, a stretch of railway track intersected by a highway, 3. signal located at the intersection of said stretch and said highway, said signal being capable of I displaying three indications, means efi'ective when no train is approaching said highway on said stretch for causing said signal to display a first one of said indications, means effective when a train enters said stretch and until the train has passed a first point located a predetermined distance in rear of said highway for causing said signal to display a second one of said indications, means effective after said train has passed said first point and until the train has passed the highway for causing said signal todisplay the third one of said indications, and means effective after said train has passed said highway for causing said signal to again display said first indication.

14. In combination, a stretch of railway track over which trafiic moves in both directions, said stretch being intersected at an intermediate point by a highway, a highway crossing signal capable of displaying three indications located adjacent the intersection of said stretch and said highway, means efl'ective when said stretch is unoccupied for causing said signal to display a first one of said indications, means eifective when a train moving in either direction enters said stretch and until said train is within a predetermined distance from said highway for causing said signal to display a second one of said indications, and means eflective after said train is within said predetermined distance from said highway and until after the train has passed said. highway for causing said signal to display the third one of said indications.

15. In combination, a stretch of railway track over which traific moves in both directions, said stretch being intersected at an intermediate point by a highway, a highway crossing signal capable of displaying three indications located adjacent the intersection of said stretch and said highway, means effective when said stretch is unoccupied for causing said signal to display a first one of said indications,means effective when a train moving in either direction enters said stretch and until said train is within a predetermined distance from said highway for causing said signal to display a second one of said indications, means effective after said train is within said predetermined distance from said highway and until after the train has passed said highway for causing said signal to display the third one of said indications, and means ,efi'ective as soon as said train has passed beyond said highway for again causing said signal to display said first indication.

16. In combination, a stretch of railway track over which trafiic moves in both directions, said stretch being divided into first, second, third and fourth successive sections, a highway intersecting said stretch-at substantially the junction of said second and third sections, a highway crossing signal capable of displaying three indications located adjacent the intersection of said stretch and said highway, means efi'ective when all of said sections are unoccupied for causing said signal to display a first one of said indications, means effective when either said first or said fourth section is occupied by a train approaching said highway for causing said signal to display a second one of said indications, and means effective when either said second 01 said third section is occupied by a train approaching said highway for causing said signal. to display a third one of said indications.

17. In combination, a stretch of railway track over which traffic moves in both directions, said stretch being divided into first, second, third and fourth successive sections, a highway intersecting said stretch at substantially the junction of said second and third sections, a. highway crossing signal capable of displaying three indications located adjacent the intersection of said stretch and said highway, means etfective when all of said sections are unoccupied for causing said signal to display a first one of said indications, means efi'ective when either said first or said fourth section is occupiedby a train approaching said highway fol-causing said signal to display a second one of said indications, means efiective when either said second or said third section is occu ied by a train approaching said highway f dr causing said signal to display a third one of said indications, and means effective after the train has passed said highway for again causing said signal to display said first indication.

18. In combination, a stretch of railway track divided into four successive sections, a highway crossing said stretch adjacent the junction of the two inner sections, a first interlocking relay having two magnets controlled by traific conditions in said two inner sections respectively, two track relays controlled by traflio conditions in the two outer sections respectively, a second interlocking relay having two magnets one controlled by one magnet of said first interlocking relay and by one track relay and the other controlled by the remaining magnet of said first interlocking relay and by the other track relay, and a signal controlled by said two interlocking rela s.

ln testimony whereof I aflix my signature.

CHARLES W. BELL. 

